Apparatus for removing noncondensible gases from refrigerating systems



J. F. WEAVER Feb. 25, 1936,

APPARATUS FOR REMOVING NONCONDENSIBLE GASES FROM REFRIGERATING SYSTEMS Filed Nov. 3, 1934 ATTORN E! Patented Feb. 25, 1936 STATES PATENT OFFICE APPARATUS FOR REMOVING NONCON- DENSIBLE GASES FROM REFRIGERATING 1 SYSTEMS 1 Claim.

This invention relates to commercial refrigeration and it has particular reference to a method and apparatus designed to purge a refrigerating system of objectionable non-condensible gases.

The principal object of the invention is to provide apparatus of an extremely simple and easily operated construction which is adaptable to that type of system in which ammonia is employed as the refrigerating fluid and is extremely effective in purging the system of accumulated, noncondensible gases entrained with the refrigerating fluid.

The invention further aims as one of its foremost objects to provide a method for the expul- 5': sion of the undesirable gases from a refrigerating system which consists primarily in establishing a refrigerating zone, in which is situated a subzone, in causing to pass into the sub-zone at low temperatures the refrigerating fluid with its entrained, non-condensible gases, in passing off the non-condensible gases above the fluid, in observing the fluid level in the sub-zone to determine the amount of non-condensible gases remaining in the system and in returning the con- "5- densed refrigerating fluid back to the system.

Still another object of the invention is to provide an apparatus and method for the purpose specified in which the refrigerating system may be purged of objectionable gases without inter- 36 fering with the normal operation of the plant. Moreover, the present invention does not require a reduction in the amount of refrigerating fluid used in normal operation to accomplish its results, which is necessary in certain types of purg- 35 ing apparatus to maintain the suction pressure required to obtain the desired temperature.

With the foregoing objects as paramount, the invention has particular reference to its salient features of construction and arrangement of 40 parts, which will become manifest as the description proceeds, taken in connection with the accompanying drawing, wherein:

Figure 1 shows the invention in elevation and partly in vertical section and its relationship 45 with the conventional type of receiver of a refrigerating system.

Figure 2 is an elevation of one form of thermometer well showing the manner in which it may be attached either to a closed pressure cyl- 50 inder of the invention or to any adjacent suction line of the system, and

Figure 3 is a view on lines 3-3 on Figure 2,

Since refrigerating systems employing carbonic acid, ammonia and like fluids as the refrigerat- 55 ing medium are well known to the art, it is not considered necessary to describe such a system.

It is however important to mention that in the operation of any such refrigerating system, the results obtained or the temperature maintained, depends entirely on the suction pressure maintained. When any type of purger is put into operation requiring the expulsion of additional refrigerating fluid in order to obtain the desired temperature, the amount of such fluid will necessarily have to be reduced in order to maintain 1 the suction pressure necessary for the desired temperature, therefore, the amount of work or refrigeration which would ordinarily be produced during inoperative periods of the purger would be materially reduced. Where refrigerating fluid is required to be passed through a purger to cool the same, it is impossible to utilize but a very small amount of such refrigerant, the surplus passing through and into the suction line of the system and on to the compressor, thereby reducing the superheat and resulting in a considerable drop in the efliciency of the compressor.

The foregoing condition is likewise objectionable in that the cylinders of the compressor frequently frost over which results in undue mechanical wear and loss of power. That ammonia which passes off with the suction gases and whose refrigerating effect is greatly reduced thereby is not only detrimental to the normal operation of the system, the efficiency of the machine and causing undue wear but this surplus refrigeration is a complete loss. The present invention, as previously stated, instead of being independently cooled, it is confined in an already refrigerated zone, such as an ice chamber but preferably in a brine tank and under these conditions, the amount of refrigeration utilized in refrigerating the gases is so small as to be negligible.

Continuing with a more detailed description of the drawing, l designates a brine tank for the purpose of explanation, it being understood that the unit embodying the invention will function with equal efliciency when situated in a zone at low temperatures. A cylinder 2 is partially submerged in the brine and has closed ends 3. Condensed refrigerating fluid enters the pipe 4 of the receiver 5 from the condenser, not shown, and is normally passed on through the liquor line 6a to the expansion coils, not shown.

Under ordinary operating conditions, the non- 5 condensible gases entrained with the fluid likewise pass with the fluid to the receiver, thereby causing excessive head pressures which are detrimental to the operation of the system in two ways. First, by increasing the power used to operate the compressor and reducing the amount zone or chamber 2, it being understood that both' the valves 8 and 9 are opened to carry out this operation.

Manual attendance is ordinarily not required, thepurger being entirely. automatic, however, the valve In in the pipe I I being closed, the liquor entrapped within the chamber 2 cannotescape and.

the non-condensible gases ascendingthrough the liquified column of refrigerating fluid is drawn off through the pipe l2, through valve 13 and .re-

leased to atmosphere through the pipe I4. It

is desirable to provide a container, preferably transparent in'which to submerge the pipe I4 in order to visibly indicate the volume of non-con? ,clensible'gases escaping from the system. Ebullition of thecon-tents of the container will definitely show that gasesare escaping from the system. Should the valves be'opened too long or if there is but a small amount of non-condensible gases in the-system; the operator may at once determine this by the distinctive odor arising from the container which has not been illustrated, and take precautions to correct the condition either by closing the valve partially or entirely.

" A sight indicator 15 is provided, for communi- V cation with the chamber 2 through pipes 11.6 and i7 controlled by valves 18 and I9. When the system is thoroughly purged, the liquor rises in the chamber 2 and maybe observed in theindicator l5, whereupon'the engineer closes valves 9' and I3 and' opens valve 10 whereupon theliquor or liquified refrigeratingfluid is withdrawn from the chamber 2 and is returned to the system throughthepipe H. p. 7

It is apparent from the foregoing that no .loss of refrigeratingpfluid occurs during the extraction of air and other non-condensible gases from the system. V

Undercertain conditions, where it is not desired to employ a .sight'indicator such as shown at l5, a thermometer 20 maybe substituted and may be affixed either to the chamber 2 or to any part of the adjacent liquor line which may, for

the purpose, of illustration, be designated by the reference character 2|. 'By employing this thermometer as indicated, an expert refrigerating engineermay determine the amount of non-condensible gases circulated in the system.

A novel means of supporting the thermometer relative to the line is shown in Figures .2 and 3' and is comprised of a clamp in the form of a band 22, secured to the line by a bolt 23. A pocket 24 is providedon the band adapted to contain ammonia oil, mercury or other suitable material having high conductive properties and to this pocket is afiixed a thermometer well 25 to receive the thermometer .20. Asstated, the device shown in Figures 2 and 3 and just described may be substituted for the sight indicator 15 or may be used independently thereof at any point in the system where it is possible to determine by temperature tests the amount of non-condensible gases in the system. 'It is of course obviousthat undue frosting of pipes and other equipment may be used as a meansfor detecting air in the system but 7 the present invention and its appurtenances are such that "such a means is rendered unnecessary particularly since conditions such as these incur avoidable expenses'and trouble.

Manifestly, the. construction shown is capable of some modification and such modification as is considered within the scope and meaning of the appended claims isalso considered'within the spirit and intent of the invention.

What" is claimed is? 3 In an apparatus for removing non condensible gases from refrigerating systems, the combine;-

tion comprising a receiver for refrigerating fluid,

a brine tank, a closed vertically disposed 'cylindrical chamber partially submerged in the brine chamber to effect escape'of non-condensible gases accumulating in said chamber, valve means in control of fluid entering and leaving said chamber, visible means for determining the level i of the liquid in said chamber and means for returning the liquid to said system subsequent 'to thewithdrawal of said non-condensible gases. JOHN FRWEAVER 

